Process of preventing oxidation of metals during annealing.



PATENT OFFICE.

JOHN F. 'rnomrson, or BROOKLYN, AND EDWARD n sEnLYn oF romrxrnsvrnnn,

NEW YORK, assronons, BY mnsnn ASSIGNMENTS, TO THE. m'rnnna'rronan NICKEL COMPANY, A. CORPORATION OF NEW JERSEY.

PROCESS OF PREVENTING QX IDATION 01 METALS DURING ANNEALING-.

No Drawing.

Brooklyn, Kings county, New York, and -EDWARD E. SEELYE, a citizen of the United States, residin at Tompkinsville, Richmond county, New ork, have invented an Imroved Process of Preventing Oxidation of etals During Annealing, of which the following is a,specification.

Our invention relates to the annealing ofv metals and is especially directed to the prevention or elimination of oxidation on the surface of metals during the annealing operation. We have discovered that when a fusible halo en salt' of an alkaline or an alkaline-eart metal is mixed with a base and s read on the article to be annealed, that uring the annealin operation the article will not oxidize, an moreover, not

only is oxidation prevented, but such halogen salt will act' as a solventto remove any oxid on the surface of'the metalwhen it is heated for annealing. v

The following is a typical way of carry-' ing out our method: To boiling water in a suitable receptacle, we add calcium chlorid,

and the calcium chlorid is thereby dissolved in the water and forms a saturated solution of calcium chlorid. We then emulsify the mixture by adding ground fiuorspar (cal-,

cium fluorid) and the result is a mixture in the form of a thin paste. To this, if desired, we may add-more water for the purpose of thinning the mixture. We then apply the paste to the article to be annealed by either dipping the article into the paste or by app ing the paste to the article with a brus When the article is heated, its 'surfaces, instead of oxidizing, are kept free from oxidation, and after annealing the' paste can be washed, rubbed, or brushed oif,

and the surfaces of the article-are foundin the same condition in which substantiall theywere efore annealing. I f, however, thearticle was somewhat oxidizedbefore Specification of Potters Patent. Application filed March 8, 1912. Serial No. 682,538.

been removed during the annealingo era-v -tion, the mixture acting as a solvent tore-'- for during the heating operation. In the typical method weusually employ two parts of fiuorspar to one part of calcium 'chlorid, the-calcium'chlorid being the active agent and the fiuorspar being the base which retains the calcium chlorid' on the surface of Patented Feb. 3, 1914. a

the article when the calcium chlorid fluxes from the heat during the annealing process.

The base employed must act as a vehicle to retain the active a em on the surfaces of the articles during t e annealing temperatime since if the mixture is not retained on the surfaces of the articles 'in a uniform.

manner, oxidization will ensue} The water is added to aid in spreading the mixture on the-article to be annealed.

The proportions of the base and of the fusible halogen salt of an alkaline-earth. metal may be varied.within certain limits in the practice of our invention, and any material may be used instead of the calcium composed of fiuorspar and calcium ohlorid,

and then heating the articles for annealing thereby preventing oxidation of the articles during annealing.

2. The process of annealing" metallic articles, which consists in applying to the surfaces to be annealed, a mixture composed of two parts calcium fluorid and one part calcium chlorid, and then, heatin the articles for annealing thereby p'reventmg oxidation ofthe articles during annealing.

3. The process of annealing metallic articles, which consists in applying to the suroan-ma faces to be annealed, an emulsion composed nealed a mixture comprised of calcium of calcium fluorid, calcium chlorid and fluorid and a fusible halogen salt of an 10v Water, aml then heating the articles for an alkaline metal. healing thereby preventing oxidation of the I 5 articles during annealing. I

' 4. The process of preventing oxidization Witnesses: during annealing, which consists in 'apply- Lucius R. COSTIZA, ing to the surfaces of the articles to be an- LUKE E. GRAHAM.

JOHN F. rnorson. EDWARD E. SEELYE. 

